The W.M. Keck Observatory and its two 10-meter-wide telescopes are located on the top of Mount Mauna Kea in Hawaii. Sensitive to optical and infrared light, these dual-lens telescopes are among the largest and most productive instruments in the world. Every night, they enable astronomers to observe objects as close to our solar system as possible, as well as some of the earliest galaxies in the universe. The Keck Observatory has two 10 meter long mirrors, each consisting of 36 hexagonal elements that work together as a mirror. Each mirror weighs 300 tons and is supported by 270 tons of steel. Each telescope dome has a volume of more than 700,000 cubic feet. The dome cools throughout the day and stays at or below freezing to prevent the mirror from deforming due to heat. The Keck Observatory is the first major facility to use adaptive optics and laser guides. It now uses nearly a dozen instruments to image and study the sky. Future instruments include planetary detectors and cosmic plotters. The W.M. Keck Observatory uses the most advanced instruments to observe the universe, including some light that helps it dissect distant objects. These spectrometers and infrared cameras keep Keck at the forefront of astronomical research. In recent years, the Observatory has also installed adaptive optics to help its mirrors compensate for atmospheric motion that may blur the field of view. These systems use lasers to create “guide stars” in the sky.